---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Sun 09/09/07: 18 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:52 AM - Re: Heated pitot retrofit (Marty Helller) 2. 03:34 PM - VM1000 manifold pressure and CHT sensors (sarg314) 3. 03:51 PM - Re: VM1000 manifold pressure and CHT sensors (Vanremog@aol.com) 4. 04:12 PM - Re: VM1000 manifold pressure and CHT sensors (sarg314) 5. 04:13 PM - Re: VM1000 manifold pressure and CHT sensors (Larry Pardue) 6. 04:35 PM - Re: VM1000 manifold pressure and CHT sensors (Kevin Horton) 7. 04:46 PM - Re: VM1000 manifold pressure and CHT sensors (sarg314) 8. 04:50 PM - Re: VM1000 manifold pressure and CHT sensors (Tim Bryan) 9. 05:23 PM - Re: VM1000 manifold pressure and CHT sensors (Larry Pardue) 10. 05:37 PM - Re: VM1000 manifold pressure and CHT sensors (Kevin Horton) 11. 06:37 PM - Re: VM1000 manifold pressure and CHT sensors (sarg314) 12. 06:42 PM - Re: VM1000 manifold pressure and CHT sensors (sarg314) 13. 07:00 PM - Re: VM1000 manifold pressure and CHT sensors - a formula (sarg314) 14. 07:11 PM - Relays used on Flap / Trim Motor Control (Garey Wittich) 15. 07:31 PM - Re: Relays used on Flap / Trim Motor Control (vft@aol.com) 16. 09:08 PM - Re: Relays used on Flap / Trim Motor Control (Ken Cantrell) 17. 09:38 PM - Re: Relays used on Flap / Trim Motor Control (Paul Besing) 18. 11:17 PM - Re: Relays used on Flap / Trim Motor Control (Doug Gray) ________________________________ Message 1 _____________________________________ Time: 08:52:21 AM PST US From: "Marty Helller" Subject: RE: RV-List: Heated pitot retrofit Karl, Just done it also..... put my Gretz tube in the bay next to the wing access panel (wingtip side) - Thoughts to consider..... figure how you will countersink the skin before doing any riveting. I didn't and a fellow builder recommended I build a countersunk backplate. By using a countersunk screw I was able to pull the skin into a somewhat countersunk area.... but it isn't pretty. - Riveting.... you'll need to poprivet the support brackets.... - The smart chip (circuit board) Seemed to challenging to install the platenuts on the rib, so I built a raised platform to mount the chip right on the access panel but ensured the back of the circuit panel didn't touch the aluminum access plate. - Connecting the pitot line. Have to move the installed (aluminum) line to the new position. Bought a 1/4 by 1/4 copper pipe connector in the Home Depot aviation isle. Haven't bent the copper tube on the Gretz unit yet, but feel it's necessary to avoid a right angle in the pitot static line. On the road, so I don't have pictures..... Hope this helps.... Marty RV-7 (N622HR) Fitting systems in the fuselog... >From: "Karl Ahamer" >To: >Subject: RV-List: Heated pitot retrofit >Date: Fri, 7 Sep 2007 13:48:07 +1000 > >Hi all, >Wonder who difficult it would be to fit a heated pito tube once the >skins are on the wing (RV7),but wings not fitted to the fuselage as yet. >Anyone done this before? > >Regards >Karl Ahamer >7A near Sydney/Australia > > >6/09/2007 3:18 PM > > >6/09/2007 3:18 PM > _________________________________________________________________ Kick back and relax with hot games and cool activities at the Messenger Caf. http://www.cafemessenger.com?ocid=TXT_TAGHM_SeptHMtagline1 ________________________________ Message 2 _____________________________________ Time: 03:34:45 PM PST US From: sarg314 Subject: RV-List: VM1000 manifold pressure and CHT sensors I have a VM1000 that has sat in a box for 6 years. VisionMicro (=JPI) tells me they have an inventory of VM1000 spare parts but are not going to maintain it any more. When those parts are gone, they're gone forever. I finally got the VM1000 installed and powered up. It was flaky until I reseated the 4 socketted DIP components in the main control box. I attribute that to sitting unused for so long (and maybe cheap sockets). Seems to come up reliably now, but shows 2 problems. The CHT3 is consistently 15 - 20 deg. low and the manifold pressure is about 2.5 inches low. It reads 27.3 when the barometric pressure is 30.00. The M.P. sensor is a bellows type and can get stuck, so the tech at Vision Micro recommended I just run the engine a bit. Well, I'm a few months away from being able to do that and their inventory of spare parts is only getting smaller, so rather than wait, I hooked up a hose to it and actually blew into it gently. I was able to make it change +- 1 inch, so I don't think I did it any violence. But it still returns to 27.3 in. when I leave it be. There must be lots of people out there with experience with these things. Should I spend the $250 to buy a new MP sensor now, or wait until the engine is actually running and hope that all the vibration and pressure swings will get the thing working, OR that Vision Micro will still have sensors on the shelf? Since the CHT is a thermocouple, it is as likely that the failure is the amplifier circuit it is connected to as it is a bad thermocouple. I don't know anything about the innards of these things. What is the typical failure mode for a VM1000 temp. sensor? Is it the sensor itself or the circuitry reading it? All the other thermo probes seem OK. Thanks, -- Tom Sargent, RV-6A, electrical system ________________________________ Message 3 _____________________________________ Time: 03:51:07 PM PST US From: Vanremog@aol.com Subject: Re: RV-List: VM1000 manifold pressure and CHT sensors In a message dated 9/9/2007 3:36:20 P.M. Pacific Daylight Time, sarg314@comcast.net writes: Since the CHT is a thermocouple, it is as likely that the failure is the amplifier circuit it is connected to as it is a bad thermocouple. I don't know anything about the innards of these things. What is the typical failure mode for a VM1000 temp. sensor? Is it the sensor itself or the circuitry reading it? ===================================== Easy to swap the TC out with one of the others and see if the problem moves with it. Regarding the MP sender, it seems a stretch to me that benign storage could cause it to drift in this fashion to that degree. I would try to find someone else out there in RV builder land with another identical sender that you could swap out to see if this is the culprit. Either that or go thru all of the printed troubleshooting tips that VM gives out to try and pinpoint the problem (low voltage to the sender, wrong output, high resistance at the connections, bum wire). N1GV (RV-6A, Flying 865hrs, O-360-A1A, C/S, Silicon Valley) ________________________________ Message 4 _____________________________________ Time: 04:12:31 PM PST US From: sarg314 Subject: Re: RV-List: VM1000 manifold pressure and CHT sensors Thanks, I guess I'll have to swap CHT sensors. I don't like handling those things - I keep expecting that stiff T.C. wire to fatigue and break. I was looking for a "trouble shooting" section in the manual, but mine doesn't have one. I didn't get anything else with the unit and their web page has no downloads. How did you get yours? Vanremog@aol.com wrote: > Either that or go thru all of the printed troubleshooting tips that VM > gives out to try and pinpoint the problem (low voltage to the sender, > wrong output, high resistance at the connections, bum wire). > > > *N1GV (RV-6A, Flying 865hrs, O-360-A1A, C/S, Silicon Valley)* ________________________________ Message 5 _____________________________________ Time: 04:13:31 PM PST US From: Larry Pardue Subject: Re: RV-List: VM1000 manifold pressure and CHT sensors On Sep 9, 2007, at 4:33 PM, sarg314 wrote: > > I have a VM1000 that has sat in a box for 6 years. VisionMicro > (=JPI) tells me they have an inventory of VM1000 spare parts but > are not going to maintain it any more. When those parts are gone, > they're gone forever. > > I finally got the VM1000 installed and powered up. It was flaky > until I reseated the 4 socketted DIP components in the main control > box. I attribute that to sitting unused for so long (and maybe > cheap sockets). Seems to come up reliably now, but shows 2 > problems. The CHT3 is consistently 15 - 20 deg. low and the > manifold pressure is about 2.5 inches low. It reads 27.3 when the > barometric pressure is 30.00. What do you mean by when the pressure is 30.00, the altimeter setting? What is your altitude? If your elevation is around 2,700 feet the MP is probably correct. Larry Pardue Carlsbad, NM ________________________________ Message 6 _____________________________________ Time: 04:35:40 PM PST US From: Kevin Horton Subject: Re: RV-List: VM1000 manifold pressure and CHT sensors On 9 Sep 2007, at 18:33, sarg314 wrote: > > ... the manifold pressure is about 2.5 inches low. It reads 27.3 > when the barometric pressure is 30.00. The M.P. sensor is a > bellows type and can get stuck, so the tech at Vision Micro > recommended I just run the engine a bit. Well, I'm a few months > away from being able to do that and their inventory of spare parts > is only getting smaller, so rather than wait, I hooked up a hose to > it and actually blew into it gently. I was able to make it change > +- 1 inch, so I don't think I did it any violence. But it still > returns to 27.3 in. when I leave it be. What is the source of the barometric pressure you are using to compare the MP indication against? Is it really the true barometric pressure, or is it possible that it is sea level corrected barometric pressure? What is the elevation of your shop, roughly speaking? Kevin Horton RV-8 (finishing kit) Ottawa, Canada http://www.kilohotel.com/rv8 ________________________________ Message 7 _____________________________________ Time: 04:46:10 PM PST US From: sarg314 Subject: Re: RV-List: VM1000 manifold pressure and CHT sensors Larry: I am at 2200 ft. altitude. The 30.00 is what I'd uses as the altimeter setting. I didn't think 2200 ft would account for 2.7 in. of pressure difference, but I admit I was just guessing. Larry Pardue wrote: > What do you mean by when the pressure is 30.00, the altimeter > setting? What is your altitude? If your elevation is around 2,700 > feet the MP is probably correct. > > Larry Pardue > Carlsbad, NM > ________________________________ Message 8 _____________________________________ Time: 04:50:50 PM PST US From: "Tim Bryan" Subject: RE: RV-List: VM1000 manifold pressure and CHT sensors Tom, Is this already all installed in your airplane? I have an original VM1000 and if it wasn't installed I would drop it like a rock. It would be a hard decision because of what I spent for the system, but I would change mine out even now if the sensors were compatible with something else. I had a bad DPU resulting in no oil pressure reading. I have been flying with a mechanical oil pressure gauge installed under the dash for 10 months. I finally got it taken care of but it took a lot including a flight to VM. I would be very surprised if they had any spare parts at all. In fact I would be very surprised how much longer they will even have parts. JPI bought them out but they are kind of like little orphans stuck in a little hanger in Texas with little to no facilities. My hangar at home is better equipped than VM. If it isn't installed, have you asked them about upgrading (actually downgrading cost wise) to the VM1000c version? I would steer completely away from VM but since you have it they might swap you for a VM1000C latest version. Anyway, just my thoughts. I am not happy with them and was very un-impressed when I went to their facility. It actually wasn't a facility at all. Tim > -----Original Message----- > From: owner-rv-list-server@matronics.com [mailto:owner-rv-list- > server@matronics.com] On Behalf Of sarg314 > Sent: Sunday, September 09, 2007 5:34 PM > To: rv-list@matronics.com > Subject: RV-List: VM1000 manifold pressure and CHT sensors > > > I have a VM1000 that has sat in a box for 6 years. VisionMicro (=JPI) > tells me they have an inventory of VM1000 spare parts but are not going > to maintain it any more. When those parts are gone, they're gone forever. > > I finally got the VM1000 installed and powered up. It was flaky until I > reseated the 4 socketted DIP components in the main control box. I > attribute that to sitting unused for so long (and maybe cheap sockets). > Seems to come up reliably now, but shows 2 problems. The CHT3 is > consistently 15 - 20 deg. low and the manifold pressure is about 2.5 > inches low. It reads 27.3 when the barometric pressure is 30.00. The > M.P. sensor is a bellows type and can get stuck, so the tech at Vision > Micro recommended I just run the engine a bit. Well, I'm a few months > away from being able to do that and their inventory of spare parts is > only getting smaller, so rather than wait, I hooked up a hose to it and > actually blew into it gently. I was able to make it change +- 1 inch, > so I don't think I did it any violence. But it still returns to 27.3 in. > when I leave it be. > > There must be lots of people out there with experience with these > things. Should I spend the $250 to buy a new MP sensor now, or wait > until the engine is actually running and hope that all the vibration and > pressure swings will get the thing working, OR that Vision Micro will > still have sensors on the shelf? > > Since the CHT is a thermocouple, it is as likely that the failure is the > amplifier circuit it is connected to as it is a bad thermocouple. I > don't know anything about the innards of these things. What is the > typical failure mode for a VM1000 temp. sensor? Is it the sensor itself > or the circuitry reading it? All the other thermo probes seem OK. > > Thanks, > -- > Tom Sargent, RV-6A, electrical system > > > > ________________________________ Message 9 _____________________________________ Time: 05:23:14 PM PST US From: Larry Pardue Subject: Re: RV-List: VM1000 manifold pressure and CHT sensors The rough rule of thumb for lower altitudes is one inch per thousand. The altimeter setting is an entirely different thing than the true pressure. Larry On Sep 9, 2007, at 5:45 PM, sarg314 wrote: > > Larry: > I am at 2200 ft. altitude. The 30.00 is what I'd uses as the > altimeter setting. I didn't think 2200 ft would account for 2.7 > in. of pressure difference, but I admit I was just guessing. > Larry Pardue wrote: > >> What do you mean by when the pressure is 30.00, the altimeter >> setting? What is your altitude? If your elevation is around >> 2,700 feet the MP is probably correct. >> >> Larry Pardue >> Carlsbad, NM >> > > ________________________________ Message 10 ____________________________________ Time: 05:37:13 PM PST US From: Kevin Horton Subject: Re: RV-List: VM1000 manifold pressure and CHT sensors There is a big difference between altimeter setting and barometric pressure. At sea level they would be the same thing. If the altimeter setting is 29.92, that just means that the barometric pressure at that location is the same as the standard atmosphere pressure for that elevation. The standard pressure for 2200 ft elevation is 27.62 " HG, so your MP gauge should read somewhere around that value, depending on whether the pressure of the day is higher or lower than a standard atmosphere. The altimeter setting is just a way to adjust the altimeter to account for non standard pressure. 2200 ft elevation with an altimeter setting of 30.00 gives a pressure altitude of 2127 ft, and the standard pressure for that altitude is 27.69 inches of mercury. So, the MP indication should have been 27.7, which isn't a huge amount different from the 27.3 that you reported. You might have a small error, but in my experience many MP gauges have errors of around 0.5". HG. Kevin Horton On 9 Sep 2007, at 19:45, sarg314 wrote: > > Larry: > I am at 2200 ft. altitude. The 30.00 is what I'd uses as the > altimeter setting. I didn't think 2200 ft would account for 2.7 > in. of pressure difference, but I admit I was just guessing. > Larry Pardue wrote: > >> What do you mean by when the pressure is 30.00, the altimeter >> setting? What is your altitude? If your elevation is around >> 2,700 feet the MP is probably correct. >> >> Larry Pardue >> Carlsbad, NM >> ________________________________ Message 11 ____________________________________ Time: 06:37:07 PM PST US From: sarg314 Subject: Re: RV-List: VM1000 manifold pressure and CHT sensors Kevin: That's awfully close. I'd better check this before I "fix" the MP sensor. I guess I was shooting from the hip on that one. Thanks. Kevin Horton wrote: > > There is a big difference between altimeter setting and barometric > pressure. At sea level they would be the same thing. If the > altimeter setting is 29.92, that just means that the barometric > pressure at that location is the same as the standard atmosphere > pressure for that elevation. The standard pressure for 2200 ft > elevation is 27.62 " HG, so your MP gauge should read somewhere > around that value, depending on whether the pressure of the day is > higher or lower than a standard atmosphere. > ________________________________ Message 12 ____________________________________ Time: 06:42:52 PM PST US From: sarg314 Subject: Re: RV-List: VM1000 manifold pressure and CHT sensors Tim: Thanks for relating your recent experiences. I'm afraid I'm "married" to the thing at this point. It's fully installed. These things seemed to be the way to go 5 or 10 years ago, but I guess they are quite dated now. The JPI buy out certainly doesn't help. Advice to other builders who aren't as far along as I am: Don't buy the expensive, complicated electronic stuff until you really have to in order to proceed. This stuff changes fast and gets smarter and more cost effective as time goes on. I bought the VM1000 because I was offered a good price just before a price hike was going to happen. Of course, I didn't think it was going to take me this long to finish the plane at that time, but that's a different problem. Tim Bryan wrote: > > >Tom, > >Is this already all installed in your airplane? I have an original VM1000 >and if it wasn't installed I would drop it like a rock. It would be a hard >decision because of what I spent for the system, but I would change mine out >even now if the sensors were compatible with something else. > > -- Tom Sargent ________________________________ Message 13 ____________________________________ Time: 07:00:54 PM PST US From: sarg314 Subject: Re: RV-List: VM1000 manifold pressure and CHT sensors - a formula I found an absolute air pressure calculator at the link below. http://www.csgnetwork.com/barcorrectthcalc.html When I fill in the numbers it gives me a 2.02 in. hg correction, so I have a 0.7 in. error, not a 2.7 in error. -- Tom S. ________________________________ Message 14 ____________________________________ Time: 07:11:35 PM PST US From: Garey Wittich Subject: RV-List: Relays used on Flap / Trim Motor Control Greetings: Does anybody have a recommendation (Mfg, Part No.) for Relays that they have used to control the direction of the Flap and Trim (Az & Elev) Motors ??? Thanks, Garey ________________________________ Message 15 ____________________________________ Time: 07:31:45 PM PST US Subject: Re: RV-List: Relays used on Flap / Trim Motor Control From: vft@aol.com http://www.aircraftextras.com/ Danny Melnik F1 #25 Melbourne (FL) Rocket Factory -----Original Message----- From: Garey Wittich Sent: Sun, 9 Sep 2007 10:10 pm Subject: RV-List: Relays used on Flap / Trim Motor Control Greetings: Does anybody have a recommendation (Mfg, Part No.) for Relays that they have used to control the direction of the Flap and Trim (Az & Elev) Motors ??? Thanks, Garey ________________________________________________________________________ Email and AIM finally together. You've gotta check out free AOL Mail! - http://mail.aol.com ________________________________ Message 16 ____________________________________ Time: 09:08:51 PM PST US From: "Ken Cantrell" Subject: RE: RV-List: Relays used on Flap / Trim Motor Control Hello, I'm in the process of replacing the relay for my elevator trim. The people at Ray Allen Co. are really helpful. Until recently, mine has been trouble free for over 5 years and 650 hours. Check there website @ http://www.rayallencompany.com/ Ken Cantrell -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of Garey Wittich Sent: Sunday, September 09, 2007 7:11 PM Subject: RV-List: Relays used on Flap / Trim Motor Control Greetings: Does anybody have a recommendation (Mfg, Part No.) for Relays that they have used to control the direction of the Flap and Trim (Az & Elev) Motors ??? Thanks, Garey ________________________________ Message 17 ____________________________________ Time: 09:38:57 PM PST US From: Paul Besing Subject: Re: RV-List: Relays used on Flap / Trim Motor Control Radio Shack sells many. I put a wiring diagram and the p/n is on there too. This is only one way to do it, and is for wiring two sticks on the flap circuit. There are other ways to skin that cat, like wire them so only one works at a time, etc, but this one worked out well for me. http://lacodeworks.com/besing/flap.htm Paul Besing Garey Wittich wrote: Greetings: Does anybody have a recommendation (Mfg, Part No.) for Relays that they have used to control the direction of the Flap and Trim (Az & Elev) Motors ??? Thanks, Garey --------------------------------- Need a vacation? Get great deals to amazing places on Yahoo! Travel. ________________________________ Message 18 ____________________________________ Time: 11:17:41 PM PST US Subject: Re: RV-List: Relays used on Flap / Trim Motor Control From: Doug Gray Nice simple idea but don't hit both the up and down switches together! You will pop your flap breaker. Doug Gray On Sun, 2007-09-09 at 21:38 -0700, Paul Besing wrote: > Radio Shack sells many. I put a wiring diagram and the p/n is on > there too. This is only one way to do it, and is for wiring two > sticks on the flap circuit. There are other ways to skin that cat, > like wire them so only one works at a time, etc, but this one worked > out well for me. > > http://lacodeworks.com/besing/flap.htm > > Paul Besing > > Garey Wittich wrote: > > Greetings: > > Does anybody have a recommendation (Mfg, Part No.) > for Relays that they have used to control the > direction of the Flap and Trim (Az & Elev) Motors ??? > > Thanks, to amazing places on Yahoo! Travel. > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rv-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RV-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rv-list Browse Digests http://www.matronics.com/digest/rv-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.